Electric heater



Nov. 13, 1928.

. J. A. WILLIAMS ET AL ELECTRIC HEATER Filed Nov 24 1926 Jib!) W/Y/fams fa eke L (1o rnl k INVENTOR;

BY vy vbL/jcli A TTORNE Y.

. e d-Na. 13.1928

contra. wIL Lms nnamaria LEQUORNIK, ormcnmounmnn New roan.

Our invention relates to electric heaters of the class in which apart of the heater is immersed in water for the purpose of heating same. It has for'its mai'n"objectto provide -'6 a heater which utilizes part of the water in which it is immersed as a part ofits electric circuit andlin which the making and breaking of the circuit is automatically governed by .the decrease and increase of the temperature of the water so that it may be'kept at an even, predetermined temperature. p

A'further object is to provide a heater very economic in its consumption of current and safe from imparting shocks or'burnstothe person using it} A still further object *is "to i i 80 bodiment of the invention.

1 provide a heater ofsimple, strong construction having no co ls, elementsor other parts likely to'burn'out or get'out of order, easy to manipulate, and'comparatively inexpensive to manufacture'j T i q These and'other objectsand advantages will be clearly understood from the following description and from the accompanying drawing of ,a preferred embodiment, but it 2 willbe; readily seen that various modifications maybem'ade without departing from the scope of theinvention. I j

Inthe drawing,

- Fig. lisa SldG'GlQVfl-tiOll .F'g. 21 is a cross-sectional, side elevation taken on line 2-.2, Fi'g.11'. a

c Fig. 3 's a cross-sectional, 'sideelevation ing various members in other positions.

ig. 4:' is axcross-sectional, bottom view taken on line 4-i4,Fig. 2. i i

Fig. 5-isa cross-sectionahtopview taken on line 5-,-5, Fig. 2. f I

Figs. 2, '3, 4 and 5 are drawn to alarger scale than-Fig.1... p v a r Referring now to all the views, "simultaneously, the heater may,'in a general way, be

. described as consisting of ahandle member from whichextends,slidably, a comparatively longtube having perforations at its lower end and enclosing an inner, sealed tube. This inner tube, having a diaphragm at its upper end, acts as a-thermostat. The switch mechanismand other parts being-containedwithin the handle member. 1

The-handle member 10 is, in this particular case, provided with a downwardly extending,

' threaded portion 11 in which the tube 1 2 is '55 free to slide. This outer tube, which has a plurality of perforations at its lower end, is

of a'preferred em anncrmc HEATER.

ippnaaa med November 24, 1926. Serial m.15o,51'o.

circular and comparatively deep chamberl i. Inside the tube 12 andconcentric'therewith, an inner tube 15 is located. This tube, the lower endof which isclosed and provided witha threaded stud 16, isalso enlarged at its upper end to form a circular, but comparatively shallow, chamber-1 7. A diaphragm 18 is placed over the upper endof the chamber 17 and securely sealed thereto. 7

Before sealing the diaphragm in place, a quantity of quickly expanding liquid, such as for example alcohol, is poured into the tube 15. A part of thefair'is also exhausted from this tube. This causesthe diaphragm, under normal temperature, to assume thedownward or inwardly-drawn position shown in Fig. 2. The tube 15 is held in itsconcentric position inside the tube 12 by means ofth'e resilient, insulating washer 19 and the insulating nut 20.' The washer 19, which rests in the bottom .of the chamber 14' and extends some distance down between the tubes, makes a water-tight joint between the tubes whenthe nut 20 is tom. y p y A cover 22 fits'over the chamber 17 and enlarged at its pper end sofas to forma screwed up tight on the stud l6'. The nut 20 is also provided with an annularshoulder :21 for correctly spacing the tubes the hot.

inside of thiscover is contained 'thejthermostaticswitch. This switch and its parts will now be described. The metal.cover .22 is I v I provided, with a 'circular' opening inlwhicha e simllartothe upperipartof Flg. 2,'but showshouldered, insulating bushing 23 is inserted.

its upper end; It'has a hole 25 drilled longitudinally through its center.

and the shoulder 29, be shape ofth is bracket, will best be understood'by'referring to Figs. 2 and 4'. I

A metal disk30 issecured to a metal rod 31 slideably mountedin the hole'25 of the metal bushing 24. ,A bow spring'32, made from a flat metal stripiand having a holethrough which the rod 31 passes, is inserted between the disk 30 and the insulating bushing '23.

Ittends to hold the disk in contact with the "arms'27. and 28 InFigs. 3 and 1, this spring This bushing is provid'ediwith a metal bushing 24; which extends some distance above has been shown in a position at right angles c to that in which it is. shown in Fig. 2. This and consequently all the parts connected "thereto, is sli deably mounted in the handle member 10. This slideable movement is limited downwardly by the .bottom of the chamber let abutting against the insulating washer 37 which restsupon the upper part of the threaded portion 11 and upwardly by a stop 38 rigidly attached .on ,the periphery of the outer tube. The stop consists of an mter mediate, metal ring39land two resilient, insulating washers 40 and 41. A compression spring e2, inserted in the handle member between the washer 36 and a metal rim 4:3 in the top otthe handle, normally tends to hold the tube in thejextended position shown in Fig. 2.

The rim 43, which is forced into the top of the handle member, is providedwith a seat for an insulating disk 44c. Two contact points 45 and4I6, having threaded, shouldered portions at? and 48, are inserted in this disk and to these are attached the main switch springs 19 and 50. These springs are held in place by the nuts 51 and 52. An insulating sleeve 53 is placed inside the handlemember s shown, thus completely insulating it from the parts contained therein.

The heater operates in the following manner:

The preferred embodiment shown is such as wouid be used with ahot water .bag, such as are commonly used in sick-rooms :tor alleviating pain. To adapt the heater to this purpose, the threaded portion 11 has been employed.

hen it is desired to heat the water in the bag, the tube 12 is inserted and the threaded portion screwed into the neck of the bag. This causes the stop 38 to abut against the seat generally provided in the neck of such bags and forces the tube and the parts attached thereto up into thehandle member. The stop also makes a water-tight, insulated joint between the heater and the bag. The upward movement otthe tube causes the topof the bushing2 t to engage with the main switch spring and the projecting shoulder 35 to engage with the other main switch spring'tt). If the contact points 45 and 4.6 are now connected to an electric current, the current will flow through spring 49,

shoulder 35, coyer 34, tube 12, through the water which has flowed in between the tubes waterbetween the tubes as the current passes through it, causes the heat which increases the temperature of the rest of the water 1n the bag. The distance between the tubes governs the resistance.

As thetemperature ot the water reaches acertain predetermined degree, the alcohol in the inner tube expands and pushes the diaphragm upward which, on account of the contact between the diaphragm and-the button 33, lifts the disk 30 from engagement with the arms 27 and 28. This breaksthe current. As the temperature of the water decreases, the diaphragm-drops and closes thecurrent.

It will be seen that by placing the proper amount of alcohol in the inner tube, :the temperature at which the water will operate the thermostatic switch may be greatly varied. It will also be noted that any injury to the inner tube will destroy the partial vacuum created therein and thus break the current.

the current is on, the action of the spring 42 immediately breaks the current ebydisengaging the main switch. These features add greatly to the safety of the device.

While we have described and illustrated a heater for use with a hot water bag, we do not wish to limit our invention to any panticular device. In like manner, while the heater illustrated employs round tubes, tubes of any other shape may be employed. Likewise, othgr liquids than water andalcohol may be use Having described our invention audits operation, what we claim 'as new and wish to I protect by Letters Patent is:

1. In an electric heater of theclass described, a metal tube, a smaller metal tube located concentrically within said first tube and electrically insulated therefrom, said inner tube closed at one end and provided with a diaphragm at the other end,-a quick expanding substance placed in said inner tube,

a switch actuated by said diaphragm, and means for connecting said outer tube and said switch to an electric current, the circuit being completed when the tubes are immersed in a liquid. 1 v

2. In an electric heater of the class described, a metal tube, a smallermetal tube located concentrically Within said first tube and electrically insulated therefrom, said inner tube closed atone end and provided with a diaphragm at the other end, aquick expanding substance placed in said inner tube, the air partly exhausted-from said inner tube, aswitch actuated by said diaphragm, and means for connecting said outer tube and said switch toan electric current, the circuitboing completed when the are immersedin a liquid-. i

3. A handle member, a metal tube projectmg from one end of said handle member, a

smaller tube located concentrically within said first tube, said tubes electrically insulated from each other and from the handle member, both tubes closed at their outer ends,

" a plurality ofperforations drilled in the partly exhausted therefrom, a switch actuated by said diaphragm, and means forcon necting said outer tube and said switch to an electric current, the circuit being completed when the tubes are immersed in a liquid. 4. A handle member, a metal tube projecting from and slideably mounted in one end of said handle member, a smaller tube located concentrically within said first tube and connected thereto, said tubes electrically insulated from eachv other and from said handle member, both tubes closed at their outer ends, a plurality of perforations drilled in the outer tube, a diaphragm provided on the other end of said inner tube, an expanding medium placed in said inner tube, a switch actuated by said diaphragm connected to the outer tube but electrically insulated therefrom, a second switch actuated by the sliding motion of said outer tube, and means for connecting said second switch and the outer tube to an electric current, the circuit being completed when the outer tube is immersed in a liquid.

' JOHN A. WILLIAMS.

EUGENE LEQUORNIK. 

